Method of making distorted crimped yarn



Sept. 13, 1966 N. ROSENSTEIN 3,271,836

METHOD OF MAKING DISTORTED CRIMPED YARN Filed April 6, 1965 FIG; 1

PM & PM

United States Patent 4 3,271,836 METHOD OF MAKING DISTORTED CRIMPED YARNNathan Rosenstein, West Hartford, Conn., assignor to Spunize Company ofAmerica, Inc., Unionville, C0nu.,

a corporation of Connecticut Filed Apr. 6, 1965, Ser. No. 445,998 3Claims. (Cl. 28-72) This application claims subject matter dis-closed inmy prior co-pending application Serial No. 214,260, filed August 2,1962, now abandoned.

This invention relates to a method of distorting or modifying thesurface of the filaments of synthetic yarn.

The prior patent to Rosenstein et al. No. 2,715,309 discloses anapparatus and method for producing crimped continuous filament yarn,such yarn comprising a synthetic material formed of V-shaped symmetricalcrimps. These crimps are formed by forcing the continuous filament yarnthrough the nip of a pair of counter-rotating crimping rollers, into azone of restriction such as a stuffing chamber or the like, in which theyarn has been accumulated, forming aback pressure, whereupon the yarn asit is fed into the zone of restriction is buckled and folded over uponitself again and again, thereby forming a multiplicity of substantiallysymmetrical V-shaped crimps.

Yarn produced according to the aforementioned patent, when formed into afabric, is quite lofty and absorbent and has a texture comparable tothat of proteinaceous fibers, often having a relatively rough feel dueto the points of the V-shaped crimp. Also, such yarn when highly crimpedhas a pronounced tendency to contract, shortening the effective pilelength when incorporated into pile fabrics. An important object of thisinvention is to provide a method of making a synthetic yarn which hasmany of the advantages of the prior art yarn just referred to, and yethas a smoother feel and a kinder, softer hand, and also has a sharplyreduced tendency to contract lengthwise. More particularly, it is anobject of this invention to provide a method of making a yarn which,when incorporated into a fabric, provides a characteristic akin to thatof a smooth worsted as compared to a rougher woolen nature.

Other objects and advantages of this invention will appear in furtherdetail hereinafter, and in the drawings whereof:

FIG. 1 is a schematic view, in side elevation, showing an apparatus andmethod for producing yarn according to this invention;

FIG. 2 is an enlarged diagrammatic view in perspective, showing oneportion of the apparatus;

FIG. 3 is an enlarged diagrammatic sectional view, taken as indicated bythe lines and arrows IIIIII which appear in FIG. 2;

FIGS. 4 and 5 are drawings representing magnifications, as indicated bythe microscope, respectively of prior art yarn and of yarn in accordancewith this invention;

FIG. 6 represents a highly enlarged view, showing a typicalrepresentative segment of prior art yarn at the location indicated bythe arrow in FIG. 4;

FIG. 7 is a greatly enlarged view of a segment of yarn according to thisinvention, as illustrated by the arrow in FIG. 5;

FIG. 8 is a sectional view of a distortion in a filament, taken asindicated by the lines and arrows VIII-VIII which appear in FIG. 7;

FIG. 9 is a plan view of the distortion appearing in FIG. 8; and

FIG. 10 is a face view of the distortion, looking as indicated by thearrows XX which appear in FIG. 9.

Referring now to the specific form of the method according to thisinvention selected for illustration in the 3"Z7 l Patented Sept. 13,1966 ice drawings, FIG. 1 shows a stuffer box crimper 10 havingoppositely rotating crimp rolls 11 forcing the yarn Y into a stulfer box12 having a release door 13, the pressure of which is controlled by acylinder 14. This apparatus (which is conventional per se) forms crimpedyarn CY composed of a multiplicty of substantially V-shaped crimps.

The number 9 designates internally arranged heating coils which may beof any desired type, such as coils carrying hot liquid or the like. Thiscauses a heat-setting of the synthetic material as it is crimped betweenthe rolls. The heat-setting means may be designed and arranged toprovide for application of heat to the crimped filaments, such asdielectric heat or a conventional autoclave, for example, and the heatmay be applied either immediately before, during or after crimping.

According to this invention, means are provided for distorting the crimpthus produced. This means includes a bar 15 having a multiplicity offlat edges 18 together with an entrance guide 16 and an exit guide 17.As shown, the crimped yarn CY passes through a pair of tension discs 7and snubbing bars 8, and is wrapped at least a half wrap around the bar15 (-but it may be wrapped more or less), and is pulled under strongtension by feed rollers 20, 20 which are positively driven. Thus, thecrimped yarn CY is maintained under substantial tension while it ispulled over the edge. The bar 15 is unheated and its edges do not causecurling of the yarn filaments but flatten out the V-shaped crimps aswill further appear. The yarn is also drawn over another similar bar15a, spaced from bar 15, which flattens out crimps that were not exposedto the flattening and distorting action of bar 15.

From the feed rollers 20, the distorted-crimp yarn is passed throughguides 21, 21a to a twister 22, or to any other equivalent equipmentsuch as a winder, for example.

FIG. 2 shows some of the details of construction of a crimp-distortionapparatus capable of performing the method according to this invention.The bar 15 is provided with sleeves 23, 23 which are adjustable aroundthe axis, thus providing for increasing or decreasing the amount of wrapof the crimped yarn CY around the bar 15, this being governed by thepositions of the guides 16, 17. The number of wraps, for a hexagonal barand for 70 denier 34 filament nylon, may vary from about one-half totwo. Bar 15a, positioned at about right angles to bar 15, does not needany guides but they may be provided if necessary in other specificarrangements, and they may also be angularly adjustable.

As shown in FIG. 3, the bar 15 is hexagonal and has six flat edges, anynumber of which may be brought into effective use by simply varying thepositions of the respective guides 16, 17. Bar 15a, similarly, ishexagonal as shown, but either bar may have any number of edges.

FIG. 4 shows a highly magnified view, as seen through a microscope, orprior art stulfer box crimped yarn, showing a considerable number ofV-shaped crimps which have been formed by folding the yarn over and overupon itself, and by subjecting the folded portions to mechanicalpressure within the stuffer box. By way of contrast, FIG. 5 showssimilar yarn which has been subjected to the special crimp-distortingprocedure of this invention. FIG. 5 shows filaments which arecharacterized by flattened, enlarged deformities, which have beenproduced by drawing the V-shaped crimps (particularly the apices of theVs) under tension angularly over the flat edge of the rod 15. These areformed by wiping or scraping the yarn over the fiat edge, afterheat-setting, and are responsible for the smoother feel and kinder handof fabrics produced from the yarn. The flattening of the crimps isbelieved to be analogous to hammering on a sharp fold or bend in metal,in an attempt to straighten it, which produces a flattening eflect wherethe metal was bent.

It is important to observe that the yarn filaments have only a fewresidual V-shaped crimps. The great majority of crimps have beenflattened, leaving the apices of the VS in a variety of distortedconditions, some of them twisted as well as flattened. These knobs ordistortions are permanent and no further heat-setting is required.

FIGS. 6 and 7 illustrate schematically the nature of the modificationthat is understood to take place. As appears in FIG. 6, many of theV-shaped crimps are partially flattened due to the fact the yarn hasbeen bent back upon itself and then subjected to high mechanicalpressure. Thus, when the yarn is subjected to tension, and such surfaceirregularities are drawn over the sharp edge of bar 15, suchirregularities are flattened, producing the type of surface deformities(distorted crimps) shown schematically in FIG. 7. Also, the V-shapedcrimps are very substantially reduced in angle.

This invention is applicable to yarn having V-shaped crimps formed inwide varieties of stuffer crimpers and in gear crimpers as well, and isnot limited to yarn produced under US. Patent No. 2,715,309.

The product of this invention differs radically and surprisingly fromordinary crimped synthetic yarn and has an extraordinarily smooth, silkyhandle which has, to my knowledge, never been provided in any texturedsynthetic yarn.

The effect, according to this invention, is achieved with filaments ofvarious cross-sections, including circular, triangular, rectangular,trilobal and others.

Although this invention has been disclosed with reference to specificforms thereof, it will be appreciated that various modifications may bemade without departing from the spirit or scope of the invention. Forexample, reversals of parts, substitution of equivalent elements forthose shown in the drawings, and the use of certain features of thisinvention independently of other features, are all intended to beincluded within the spirit and scope of this invention as defined in theappended claims.

Having thus described my invention, I claim: 1. In a method of makingdistorted crimp synthetic thermoplastic yarn the steps which comprisefolding said yarn upon itself and subjecting it to pressure whilefolded, thus forming the yarn with a multiplicity of successive V-shapedcrimps of unequal lengths which are slightly flattened at the apices ofthe Vs drawing the crimps while under tension over an edge, andcontrolling said tension to an amount for physically distorting theapices of the V-shaped crimps by Wiping action under tension intoportions of greater width than the diameter of the uncrimped portion ofthe yarn.

2. The method as defined in claim 1 wherein the crimps are drawn oversaid edge at an oblique angle to said edge.

3. In a method of making distorted crimp synthetic thermoplastic yarnthe steps which comprise forming the yarn into a multiplicity ofV-shaped crimps of unequal lengths,

heat-setting the crimps, and

drawing the seat-set crimps while under high tension over at least twosharp edges and regulating said tension to a value to cause each edge todistort physically and to change the physical shapes of the apices of asubstantial number of V-shaped crimps into portions having a greaterwidth than the diameter of the uncrimped portion of the filament.

References Cited by the Examiner UNITED STATES PATENTS 2,972,798 2/1961Stanley et al. 28-72 3,078,542 2/1963 McFarren -et al. 28-72 3,154,83511/1964 Palma et al. 28-72 FOREIGN PATENTS 558,297 12/ 1943 GreatBritain.

MERVIN STEIN, Primary Examiner.

H. S. JAUDON, Assistant Examiner.

1. IN A METHOD OFF MAKING DISTORTED CRIMP SYNTHETIC THERMOPLASTIC YARNTHE STEPS WHICH COMPRISE FOLDING SAID YARN UPON ITSELF AND SUBJECTING ITTO PRESSURE WHILE FOLDED, THUS FORMING THE YARN WITH A MULTIPLICITY OFSUCCESSIVE V-SHAPED CRIMPS OF UNEQUAL LENGTHS WHICH ARE SLIGHTLYFLATTENED AT THE APICES OF THE V''S DRAWING THE CRIMPS WHILE UNDERTENSION OVER AND EDGE, AND CONTROLLING SAID TENSION TO AN AMOUNT FORPHYSICALLY DISTORTING THE APICES OF THE V-SHAPED CRIMPS BY WIPING ACTIONUNDER TENSION INTO PORTIONS OF GREATER WIDTH THAN THE DIAMETER OF THEUNCRIMPED PORTION OF THE YARN.